| Leisure & Land Limited | Real estate | 2003 |
| Leisure & Land Management Limited | Construction | 2008 |
| Lekker Corp Limited | Information & communication | 2019 |
| Leksa Maciej Krasowski Ltd | Other services | 2016 |
| Lelliott & Co Limited | Professional & scientific | 2019 |
| Lelliotts Enterprises Limited | Construction | 2013 |
| Lemon Art Ltd | Arts & recreation | 2012 |
| Lenbie Holdings Ltd | Financial services | 2026 |
| Leney Consulting Engineers Ltd | Professional & scientific | 2026 |
| Lennox House Holdings Limited | Professional & scientific | 1991 |
| LEO International Limited | Professional & scientific | 2021 |
| Leona Properties Limited | Real estate | 2022 |
| Lera House Ltd | Real estate | 2025 |
| Leveltech Scaffolding Ltd | Construction | 2025 |
| Lewiscmcomposites Ltd | Manufacturing | 2025 |
| LEX Supply Management Limited | Professional & scientific | 2016 |
| Lexrose Ltd | Real estate | 2024 |
| Liberty Utilities Ltd | Professional & scientific | 2015 |
| Liftandthrust Limited | Extraterritorial | 2024 |
| Light Villa Residents Limited | Households | 2016 |
| Lightfoot Windows Limited | Wholesale & retail | 1990 |
| Lilisden Ltd | Arts & recreation | 2022 |
| Lilywhite Holdings Ltd | Real estate | 2025 |
| Lime Bookkeeping Ltd | Professional & scientific | 2012 |
| Limes Park Limited | Households | 2007 |
| Limitless Formula Ltd | Wholesale & retail | 2025 |
| Limitless Recovery Hub Ltd | Other services | 2025 |
| Linden Fish Bar 2025 Limited | Hospitality | 2025 |
| Lindens House (Emsworth) Management Company Limited | Real estate | 2015 |
| Lindfield Court Management Co Ltd | Households | 2017 |
| Lion Court Freehold Ltd | Households | 2017 |
| Lion Payroll & Book - Keeping Limited | Professional & scientific | 2013 |
| Lisa Armstrong Limited | Professional & scientific | 2026 |
| Lisbon Associates Limited | Real estate | 1994 |
| Liskeard Investments Limited | Real estate | 2013 |
| Litaonline Ltd | Wholesale & retail | 2024 |
| Little Birds Forest Nurseries Ltd | Health & social care | 2018 |
| Little Busy BEE Removals Ltd | Construction | 2019 |
| Little Florist Ltd | Wholesale & retail | 2016 |
| Little Learners Together Ltd | Hospitality | 2025 |
| Little Piggies Cafe Ltd | Hospitality | 2019 |
| Little Shore Chippy Ltd | Hospitality | 2025 |
| Little Wren Homes Ltd | Real estate | 2025 |
| LJC Luscombe Holdings Ltd | Financial services | 2025 |
| LJM Media Consulting Limited | Professional & scientific | 2007 |
| LJT Accountancy Ltd | Professional & scientific | 2025 |
| LL Renewables Limited | Energy | 2025 |
| Llht Properties Limited | Real estate | 2024 |
| LM Restart Limited | Administrative & support | 2019 |
| Lmclub Bungalow Ltd | Hospitality | 2013 |
| LMH Sussex Limited | Other services | 2020 |
| Local Lawns Limited | Administrative & support | 2011 |
| Local Media Ltd | Information & communication | 2020 |
| LOCUMVET4U Limited | Professional & scientific | 2020 |
| Loganberry Computer Services Ltd | Information & communication | 2013 |
| Logicagent Limited | Professional & scientific | 1983 |
| Logistics Leadership Ltd | Professional & scientific | 2018 |
| London Road Jewellery Limited | Professional & scientific | 2005 |
| London Salsa Limited | Information & communication | 2012 |
| London SEO Agency Ltd | Information & communication | 2020 |
| Longoffer Property Management Limited | Professional & scientific | 1988 |
| Look Glamorous Ltd | Other services | 2022 |
| Lord Consultancy Ltd | Professional & scientific | 2025 |
| Lordsdale Bognor Seafront Limited | Arts & recreation | 2017 |
| Lordsdale Chichester Limited | Arts & recreation | 2025 |
| Lordsdale Estates Holdings Limited | Financial services | 2017 |
| Lordsdale Estates Limited | Arts & recreation | 1987 |
| Lordsdale Littlehampton Limited | Arts & recreation | 2017 |
| Lordsdale Worthing Limited | Arts & recreation | 2017 |
| Lotus Styling Limited | Other services | 2002 |
| Louisville Patisserie Limited | Wholesale & retail | 2014 |
| Love & Birdie Ltd | Wholesale & retail | 2026 |
| Love Building & Carpentry Limited | Construction | 2012 |
| Love Developments Limited | Real estate | 2015 |
| Love Rustic Decor Limited | Wholesale & retail | 2018 |
| Love Someone Everyday Ltd | Wholesale & retail | 2025 |
| Love YOU Events Limited | Other services | 2022 |
| Lovestays Ltd | Real estate | 2026 |
| Lowbudgetremovals Ltd | Transport & logistics | 2021 |
| LP Electrical South Coast Ltd | Construction | 2025 |
| LP SD Fifty Five Limited | Wholesale & retail | 2023 |
| LQS Facilities Limited | Administrative & support | 2025 |
| LRB Capital Limited | Financial services | 2022 |
| LS Composite Laminating Limited | Professional & scientific | 2016 |
| LST Electrical Services Ltd | Manufacturing | 2024 |
| LTR& Co Ltd | Transport & logistics | 2026 |
| Lucille Graham Trust Limited | Education | 1992 |
| Luke Bacon Carpentry Ltd | Manufacturing | 2022 |
| Luke Murray Enterprises Ltd | Education | 2024 |
| Lulamae's Cafe LLP | | 2022 |
| Luvcarpets Limited | Other services | 2013 |
| Luxston Ltd | Other services | 2018 |
| Lynch Aggregates Limited | Mining & quarrying | 2025 |
| Lyons Financial Planning Ltd | Financial services | 2020 |
| M & a H Associate Ltd | Professional & scientific | 2026 |
| M Apple SON Ltd | Transport & logistics | 2016 |
| M B a Consultancy Services Ltd | Extraterritorial | 2013 |
| M G Hedley Services Ltd | Administrative & support | 2022 |
| M J Roofing (Sussex) Ltd | Construction | 2006 |
| M P Gausden Construction Services Limited | Professional & scientific | 2019 |